The present invention is directed to portable saws for cutting materials generally disposed in such a manner presenting a generally horizontal top surface, the saw making a generally vertical cut into the top surface to a desired depth. The invention is particularly directed to a suitable support structure permit easy handling of the portable saw while containing the material displaced by the cutting action of the saw. The present invention has particular utility in cutting concrete and rock, and in removing tree stumps. The present invention is principally directed to larger saws that are suited for manipulation by apparatus such as a compact hydraulic excavator vehicle like a skid-steer.
It is well known to employ a motor driven circular saw blade to cut a variety of materials including concrete. The circular saw blades come in a large variety of sizes and are powered by a similar variety of motor sizes. In some circumstances a protective guard is provided to partially surround the saw blade. Typically the guard is essentially semi-circular and is fixed to the motor driving the saw so that a portion of the saw blade is exposed to allow the saw to cut a given work piece. Often the guard includes a debris opening to permit the material removed from the work piece by the saw to be directed away from the saw blade in a preferred direction by a chute. Rarely, if ever, does the guard contribute to the control and stability of the apparatus. Often the guard prevents the operator from seeing or correctly assessing the position of the blade with respect to the work piece.
In some saws, protective guards are not present at all or are only of sufficient size to give the saw operator maximum visibility yet some minimum protection while maximizing the ability to employ the saw to make a variety of cuts. The reduction in size of the protective guard, or its total elimination, generally allows the debris cut from the work piece to become airborne and widely disbursed. In circumstances where there is likely to be considerable passing traffic, such as on highway construction projects, the airborne disbursement of debris is undesirable. Thus, there is a need for a saw that can be easily and safely handled for making cuts in concrete and other hard substances to permit removal thereof. There is a particular need for such a saw that would not allow the airborne distribution of debris from the work piece beyond the immediate vicinity of the saw blade.
Accordingly, the present invention includes a motor having a rotatable shaft and a saw blade coupled to the shaft for rotation by the motor. A plate is coupled to the motor, the plate having two ends. A housing surrounds the plate, motor and blade to contain any airborne debris. The housing includes a perimeter on a lower surface positionable to surround a work area. The enclosure is dimensions to be of sufficient lateral extent as to retain the material cut by the blade from the work area. An actuator is coupled to the housing and to the plate for displacing the plate between a fully retracted position wherein the blade is fully enclosed within the housing and an extended position wherein the blade projects from the housing into a work area.
Preferably, a portable saw apparatus of the present invention includes a motor having a rotatable shaft and a saw blade coupled to the shaft for rotation by the motor for sawing material from a work piece. A generally rectangular plate having two ends is coupled to the motor for supporting the motor. A generally rectangular housing encloses the plate, motor and blade. A pair of tracks are coupled to opposite interior walls of the housing to receive the ends of the plate for sliding vertical movement relative to the housing. A plurality of replaceable wear elements are coupled to a lower surface of the enclosure to define a perimeter of an opening. The wear elements are intended to endure placement in contiguous sliding contact with the work piece. A coupling is provided on an exterior surface of the housing for coupling the housing to a compact hydraulic excavator or similar vehicle. A hydraulic actuator is coupled to the housing and to the plate for displacing the plate along the tracks between a fully retracted position wherein the blade is fully enclosed within the housing and an extended position wherein the blade projects from the housing through the opening defined by the wear elements into position to cut material from the work piece area within the perimeter contiguous to said plane. The enclosure is of sufficient volume to retain the material cut by the blade from the work area thereby preventing the airborne distribution of debris beyond the perimeter of the enclosure. Hydraulic coupling elements are provided for coupling the powered actuator and the motor to a source of power on the compact hydraulic excavator vehicle controlled by an operator thereof. An indicator element is coupled to the plate and extends above the housing so as to be visible from the compact hydraulic excavator vehicle to signal the position of the blade relative to the housing.
One feature of the present invention is the housing surrounding the blade and motor, which is of sufficient interior volume to retain any airborne debris generated by operation of the saw. The feature has the advantage of significantly diminishing the spread of airborne dust, dirt and other detritus from the cutting action of the saw.
Another feature of the present invention is provision of replaceable wear elements to define a lower perimeter of the housing, the wear elements being intended to endure the sliding and scraping action that occurs when the saw is advanced along the length of a cut by the pushing action of the compact hydraulic excavator or similar vehicle.